Bandwidth Information Notification Method, Network Node and Communication System

ABSTRACT

A bandwidth information notification method includes: obtaining bandwidth information of a microwave link; and sending a plurality of OAM messages carrying the bandwidth information to an endpoint, wherein first one or more OAM messages of the plurality of OAM messages are sent more quickly than at least one of the rest of the plurality of OAM messages.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/816,567, filed on Aug. 3, 2015, which is a continuation of U.S.patent application Ser. No. 13/371,795, filed on Feb. 13, 2012, now U.S.Pat. No. 9,100,327, which is a continuation of International ApplicationNo. PCT/CN2010/076043, filed on Aug. 17, 2010, which claims priority toChinese Patent Application No. 200910167223.6, filed on Aug. 21, 2009.The afore-mentioned patent applications are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communicationtechnologies, and in particular, to a bandwidth information notificationmethod, a network node, and a communication system.

BACKGROUND

Internet Protocol (IP) services increase rapidly, and become amainstream service type by replacing time division multiplexing (TDM)services gradually. And network traffic also increases rapidly.Traditional Synchronous Digital Hierarchy (SDH)/Multi-Service TransportPlatform (MSTP) equipment cannot make full use of a statisticmultiplexing feature of a packet service, and cannot meet anincreasingly stringent bandwidth requirement in another aspect.Therefore, SDH equipment is being replaced by packet transport network(PTN) equipment.

Meanwhile, microwave equipment is widely applied in the operator′network. Currently, SDH microwave equipment and Plesiochronous DigitalHierarchy (PDH) microwave equipment are commonly deployed. As PTNequipment replaces SDH equipment, packet microwave equipment begins toreplace SDH/PDH microwave equipment accordingly, and is widely appliedin recent years. The packet microwave equipment refers to that packetequipment having one or more microwave interfaces.

A microwave link differs from a fiber link in that the microwave linkcan perform adaptive modulation (AM) as the weather changes, which leadsto a bandwidth change of the microwave link. Moreover, a bandwidthchange is determinate. A transport network generally requires quite highcapability of operation, administration and maintenance (OAM). However,PTN OAM functions at present are only some general operations.

The PTN OAM functions at present are only some general operations, andtherefore, the microwave link after performing adaptive modulationcannot be notified to an endpoint of a service connection which passesthrough the microwave link, which causes service congestion since theendpoint of the service connection still performs traffic controlaccording to the bandwidth information before applying adaptivemodulation.

SUMMARY

Embodiments of the present invention provide a bandwidth informationnotification method, a network node, and a communication system, so thata service connection endpoint which passes through a link may obtaincurrent bandwidth information of the link.

An embodiment of the present invention provides a bandwidth informationnotification method. The method includes obtaining bandwidth informationof a microwave link. The method also includes sending a plurality of OAMmessages carrying the bandwidth information to an endpoint, wherein whena bandwidth of the microwave link has changed, first one or more OAMmessages of the plurality of OAM messages are sent more quickly than atleast one of the rest of the plurality of OAM messages.

An embodiment of the present invention provides a bandwidth informationprocessing method. The method includes receiving, by an endpoint, aplurality of operation, administration and maintenance (OAM) messagescarrying bandwidth information of a microwave link. The method alsoincludes adjusting, by the endpoint, a service policy according to thebandwidth information.

An embodiment of the present invention further provides a network node.The network node includes a processor, configured to obtain bandwidthinformation of a microwave link. The network node also includes atransmitter, configured to send a plurality of operation, administrationand maintenance (OAM) messages carrying the bandwidth information to anendpoint, wherein when a bandwidth of the microwave link has changed,first one or more OAM messages of the plurality of OAM messages are sentmore quickly than at least one of the rest of the plurality of OAMmessages.

An embodiment of the present invention further provides a endpoint. Theendpoint includes a receiver, configured to receive a plurality ofoperation, administration and maintenance (OAM) messages carryingbandwidth information of a microwave link. The endpoint also includes aprocessor, configured to adjust a service policy according to thebandwidth information.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the accompanying drawings required fordescribing the embodiments are introduced briefly in the following.Apparently, the accompanying drawings in the following description areonly some embodiments, and persons of ordinary skill in the art may alsoderive other drawings from these accompanying drawings without makingany creative effort.

FIG. 1 is a flowchart of a bandwidth information notification methodaccording to a first embodiment of the present invention;

FIG. 2 is a flowchart of a bandwidth information notification methodaccording to a second embodiment of the present invention;

FIG. 3 is a flowchart of a service processing method according to anembodiment of the present invention;

FIG. 4 is a topology diagram of an end-to-end connection in a bandwidthinformation notification method according to a third embodiment and afourth embodiment of the present invention;

FIG. 5 is a structural diagram of a network node according to a firstembodiment of the present invention;

FIG. 6 is a structural diagram of a network node according to a secondembodiment of the present invention; and

FIG. 7 is a structural diagram of a network node according to a thirdembodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The technical solutions in the embodiments of the present invention aredescribed clearly in the following with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, theembodiments to be described are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bythose skilled in the art without any creative effort shall fall withinthe protection scope of the present invention.

A bandwidth information notification method provided in an embodiment ofthe present invention is described first. FIG. 1 illustrates a procedureof a bandwidth information notification method according to a firstembodiment. In this embodiment, a processing procedure of a network nodethat is attached by a microwave link is described, which includes thefollowing steps.

101: Detect a current modulation mode of the microwave link.

The detection may be through real-time monitoring or periodicaldetection.

102: Obtain bandwidth information of the microwave link in the currentmodulation mode.

A bandwidth of the microwave link is different in different modulationmodes, and the bandwidth of the microwave link in each modulation modeis determinate. Therefore, corresponding bandwidth information may beobtained once the current modulation mode of the microwave link isdetermined. The obtained bandwidth information may be bandwidth levelindication information or modulation mode information.

For example, an optimal modulation mode of the microwave link is 64Quadrature Amplitude Modulation (QAM), and a bandwidth in thismodulation mode is 1 Gbps; when a modulation mode is 16QAM, a bandwidthis 0.6 Gbps; therefore, when a modulation mode is 64QAM, bandwidth levelindication information may be 1 Gbps; when the modulation mode is 16QAM,the bandwidth level indication information may be 0.6 Gbps; when themodulation mode is 64QAM, modulation mode information may be a 64QAMmodulation mode; and when the modulation mode is 16QAM, the modulationmode information may be a 16QAM modulation mode. In an embodiment of thepresent invention, the bandwidth indication information may also not bea specific bandwidth value, but a number that represents the bandwidthvalue. For example, 7 represents 1 Gbps, and 5 represents 0.6 Gbps.Therefore, in the case of the 64QAM modulation mode, the bandwidth levelindication information may be 7; and in the case of the 16QAM modulationmode, the bandwidth level indication information may be 5. Specifically,which number represents which bandwidth value may be configured asrequired.

103: Send the bandwidth information to an endpoint of a serviceconnection through the service connection which passes through themicrowave link, so that the endpoint of the service connection adjusts aservice policy according to the bandwidth information.

The microwave link is one of the multiple links that are passed throughby the service connection. That is, at least one link between twonetwork nodes of the service connection is a microwave link. The serviceconnection may be an Ethernet connection, such as a Virtual Local AreaNetwork (VLAN) connection, and a Provider Backbone Bridge—TrafficEngineering Ethernet Switch Path (PBB-TE ESP) connection; and theservice connection may also be a non-Ethernet connection, such as aMulti Protocol Label Switch Label Switched Path (MPLS LSP) connection,and may also be a Label Switched Path (LSP) connection.

The bandwidth information is sent by a network node that is attached bythe microwave link through a bandwidth notification message. Thebandwidth notification message may be an Alarm IndicationSignal/Suppression (AIS) message or a new Operation, Administration, andMaintenance (OAM) message.

In an embodiment of the present invention, bandwidth information may besent to an endpoint of a service connection which passes through amicrowave link through an AIS message. An existing AIS message may beextended, so that the MS message can carry the bandwidth information.

In another embodiment of the present invention, bandwidth informationmay also be sent through a new OAM message. The new OAM message may be anewly defined OAM message, and may also be a message obtained byextending another OAM message.

It can be known from the preceding that, in this embodiment, the networknode that is attached by the microwave link may obtain the bandwidthinformation of the microwave link in the current modulation mode, andsends the bandwidth information to the endpoint of the serviceconnection which passes through the microwave link. Therefore, theendpoint of the service connection may adjust the service policyaccording to the bandwidth information, so that a bandwidth of themicrowave link can meet a service requirement, and service congestioncan be avoided.

FIG. 2 illustrates a procedure of a bandwidth information notificationmethod according to a second embodiment. In this embodiment, aprocessing procedure of a network node that is attached by a microwavelink is described, which includes the following steps.

201: Detect a current modulation mode of the microwave link.

The detection may be real-time monitoring or periodical detection.

202: Judge whether the current modulation mode is lower than an optimalmodulation mode; if the current modulation mode is lower than theoptimal modulation mode, proceed to step 203; and if the currentmodulation mode is not lower than the optimal modulation mode, proceedto step 201.

203: Obtain bandwidth information of the microwave link in the currentmodulation mode.

Specific execution may be made reference to step 102.

204: Send the bandwidth information to an endpoint of a serviceconnection through the service connection which passes through themicrowave link, so that the endpoint of the service connection adjusts aservice policy according to the bandwidth information.

Specific execution may be made reference to step 103.

It can be known from the preceding that, in this embodiment, the networknode that is attached by the microwave link may obtain the bandwidthinformation of the microwave link in the current modulation mode whenthe current modulation mode of the microwave link is lower than theoptimal modulation mode, and sends the bandwidth information to theendpoint of the service connection which passes through the microwavelink. Therefore, the endpoint of the service connection may adjust theservice policy according to the bandwidth information, so that abandwidth of the microwave link can meet a service requirement, andservice congestion can be avoided.

In the bandwidth information notification method provided in the secondembodiment of the present invention, the network node that is attachedby the microwave link obtains and sends the bandwidth information whenthe current modulation mode of the microwave link is detected as beinglower than the optimal modulation mode; and if it is detected that thecurrent modulation mode of the microwave link is the optimal modulationmode, bandwidth information may be stopped from being sent to theendpoint of the service connection which passes through the microwavelink, so that the endpoint of the service connection uses a normalservice policy to perform service processing, and ensures that amicrowave link resource is fully utilized.

FIG. 3 illustrates a procedure of a service processing method accordingto an embodiment. In this embodiment, a processing procedure of anendpoint of a service connection which passes through a microwave linkis described, which includes the following steps.

301: Receive bandwidth information of the microwave link in a currentmodulation mode, where the bandwidth information is sent by a networknode that is attached by the microwave link.

In an embodiment of the present invention, the received bandwidthinformation may be sent periodically or non-periodically by the networknode that is attached by the microwave link when the network nodedetects that the current modulation mode is lower than an optimalmodulation mode.

302. According to a preset corresponding relationship between bandwidthinformation and a service policy, determine a service policycorresponding to the received bandwidth information.

The corresponding relationship between the bandwidth information and theservice policy may be preset, so that the service policy correspondingto the bandwidth information may be determined after the bandwidthinformation is received. The service policy may specifically be aquality of service (QoS) policy, or an access control policy, or aservice switching policy.

For example, in an embodiment of the present invention, a correspondingrelationship may be preset between bandwidth information and a QoSpolicy, and therefore, after the bandwidth information is received, theQoS policy corresponding to the received bandwidth information may bedetermined, so that service processing is performed according to thedetermined QoS policy. Specifically, the endpoint of the serviceconnection may preset a corresponding relationship between bandwidthinformation and a waterline of a service buffer area. For example, whena bandwidth of the microwave link is larger, a larger service bufferarea may be set; and when a bandwidth of the microwave link is smaller,a smaller service buffer area may be set. Therefore, after receiving thebandwidth information, the endpoint of the service connection adjuststhe waterline to a position corresponding to a bandwidth that isindicated by the bandwidth information. In this way, a size of theservice buffer area is adjusted, and the QoS policy is adjusted.

In another embodiment of the present invention, a correspondingrelationship may be preset between bandwidth information and a serviceswitching policy, and therefore, after the bandwidth information isreceived, the service switching policy corresponding to the receivedbandwidth information may be determined, so that a service is switchedover to a protection path according to the determined service switchingpolicy. The service may be partly or fully switched over to theprotection path according to different service switching policies.

If multiple different bandwidth information are received, where themultiple different bandwidth information are corresponding to multipledifferent bandwidths, bandwidth information corresponding to thesmallest bandwidth is selected.

303: Perform service processing according to the service policycorresponding to the received bandwidth information.

Specifically, the service processing may be performed according to theQoS policy corresponding to the bandwidth information, or the accesscontrol policy corresponding to the bandwidth information, or theservice switching policy corresponding to the bandwidth information.

It can be known from the preceding that, in this embodiment, theendpoint of the service connection which passes through the microwavelink receives the bandwidth information of the microwave link in thecurrent modulation mode, where the bandwidth information is sent by thenetwork node that is attached by the microwave link. The service policyis adjusted according to the bandwidth information, so that a bandwidthof the microwave link can meet a service requirement, and servicecongestion can be avoided.

In another embodiment of the present invention, the network node that isattached by the microwave link obtains and sends the bandwidthinformation only when the current modulation mode of the microwave linkis detected as being lower than the optimal modulation mode; and if theendpoint of the service connection which passes through the microwavelink receives no bandwidth information within preset time, it may beconsidered that the current modulation mode of the microwave link is theoptimal modulation mode, so that the service processing is performed byusing a normal service policy, thus ensuring that a microwave linkresource is fully utilized. The normal service policy may be a normalQoS policy, or a normal access control policy, or a normal serviceswitching policy. When the service policy is a normal service switchingpolicy, the service is switched over from a protection path back to aworking path.

With specific examples, a bandwidth information notification method in athird embodiment of the present invention is described as follows.

FIG. 4 illustrates a topology of an end-to-end service connection in abandwidth information notification method according to the thirdembodiment. As shown in FIG. 4, the service connection passes through anetwork node A, a network node B, a network node C, a network node D, anetwork node E, and a network node F. A link between the network node Cand the network node D is a microwave link, and the network node A andthe network node F are endpoints of the service connection. In someembodiments, the link between the network node C and the network node Dis a microwave link, but a principle of the present invention may beapplicable to any type of communication links, for example, a satellitelink with a variable bandwidth, a passive optical network link, and adigital subscriber line link.

It is assumed that, in a normal situation, the microwave link betweenthe network node C and the network node D adopts a 64QAM modulationmode, and a corresponding bandwidth is 1 Gbps; when the environmentchanges, for example, when it rains, the modulation mode is lowered to a16QAM modulation mode, and the bandwidth decreases to 0.6 Gbps.

When detecting that a current modulation mode is lower than an optimalmodulation mode 64QAM, the network node C and the network node D send anAIS message through a service connection (may specifically be an LSP),where the AIS message is extended to carry bandwidth information of themicrowave link in the current modulation mode. Specifically, the networknode C may send the AIS message to the endpoint A or the endpoint F, anddefinitely, the network node C may also send the AIS message to both theendpoint A and the endpoint F; and the network node D sends the AISmessage to the endpoint A or the endpoint F, and definitely, the networknode D may also send the AIS message to both the endpoint A and theendpoint F.

Specifically, the AIS message may be extended to carry a link bandwidthtype-length-value (link bandwidth TLV) object, and the link bandwidthTLV object carries the bandwidth information of the microwave link inthe current modulation mode. Specifically, the bandwidth information maybe bandwidth level indication information or modulation modeinformation.

In this embodiment, the network node that is attached by the microwavelink may carry the bandwidth information through the MS message, and mayalso carry the bandwidth information through another specific type ofmessage, such as a new OAM message. The AIS message and another specifictype of message are uniformly understood as bandwidth notificationmessages. After receiving the bandwidth information of the microwavelink in the current modulation mode, the network node A and the networknode F may adjust a service policy according to the bandwidthinformation.

A specific implementation mode may be: A corresponding relationship ispreset between bandwidth information and a QoS policy on the networknode A and the network node F. When receiving the bandwidth informationof the microwave link in the current modulation mode, the network node Aand the network node F enable a QoS policy corresponding to thebandwidth information, and therefore, services are controlled atingresses (the endpoint A and the endpoint F), so that when the servicepasses through the microwave link, a congestion situation is avoided.

Another specific implementation mode may be: a correspondingrelationship is preset between bandwidth information and a serviceswitching policy on the network node A and the network node F. Whenreceiving the bandwidth information of the microwave link in the currentmodulation mode, the network node A and the network node F enable aservice switching policy corresponding to the bandwidth information, sothat a service is partly or fully switched over to a protection path.

When the environment becomes better, and the microwave link is recoveredto the optimal modulation mode, the network node C and the network nodeD stop sending the AIS message.

When no MS message that carries the bandwidth information is received inpreset time, the endpoint A and the endpoint F may use a normal servicepolicy to perform service processing.

It can be known from the preceding that, in this embodiment, the networknode that is attached by the microwave link may obtain the bandwidthinformation of the microwave link in the current modulation mode whenthe current modulation mode of the microwave link is lower than theoptimal modulation mode, and sends the bandwidth information to theendpoint of the service connection which passes through the microwavelink. Therefore, the endpoint of the service connection may adjust theservice policy according to the bandwidth information, so that abandwidth of the microwave link can meet a service requirement, andservice congestion can be avoided.

A bandwidth information notification method provided in a fourthembodiment of the present invention is described by still taking thescenario described in FIG. 4 as an example. As shown in FIG. 4, anend-to-end service connection passes through a network node A, a networknode B, a network node C, a network node D, a network node E, and anetwork node F. A link between the network node C and the network node Dis a microwave link, and the network node A and the network node F areendpoints of the service connection.

It is assumed that, in a normal situation, the microwave link betweenthe network node C and the network node D adopts a 64QAM modulationmode, and a corresponding bandwidth is 1 Gbps; when the environmentchanges, for example, when it rains, the modulation mode is lowered to a16QAM modulation mode, and the bandwidth decreases to 0.6 Gbps.

The network node C and the network node D detect a current modulationmode in real time, and send a new OAM message periodically through aservice connection (may specifically be an LSP) in a normal period. Thenew OAM message carries bandwidth information of the microwave link inthe current modulation mode. Specifically, the network node C may send anew OAM message to the endpoint A or the endpoint F, and definitely, thenetwork node C may also send the new OAM message to both the endpoint Aand the endpoint F; and the network node D sends a new OAM message tothe endpoint A or the endpoint F, and definitely, the network node D mayalso send the new OAM message to both the endpoint A and the endpoint F.When it is detected that the modulation mode changes, several OAMmessages are sent with a higher frequency, so as to notify the change ofthe bandwidth in time. Subsequently, the OAM messages are sent in anormal period. For example, a normal period of sending a new OAM messageis 1 second; and when the bandwidth changes, the first three frames ofthe new OAM message are sent in a period of 10 milliseconds, andsubsequently, a period of sending a new OAM message is restored to 1second.

Specifically, the new OAM message and the AIS message are uniformlyunderstood as bandwidth notification messages. The new OAM message maycarry a link bandwidth TLV object, and the link bandwidth TLV objectcarries bandwidth information. Specifically, the bandwidth informationmay be bandwidth level indication information or modulation modeinformation.

A specific implementation mode may be: a corresponding relationship ispreset between bandwidth information and a QoS policy on the networknode A and the network node F. When receiving the bandwidth informationof the microwave link in the current modulation mode, the network node Aand the network node F enable a QoS policy corresponding to thebandwidth information, and therefore, services are controlled atingresses (the endpoint A and the endpoint F), so that when the servicepasses through the microwave link, a congestion situation is avoided.

Another specific implementation mode may be: a correspondingrelationship is preset between bandwidth information and a serviceswitching policy on the network node A and the network node F. Whenreceiving the bandwidth information of the microwave link in the currentmodulation mode, the network node A and the network node F enable aservice switching policy corresponding to the bandwidth information, sothat a service is partly or fully switched over to a protection path.

It can be known from the preceding that, in this embodiment, the networknode that is attached by the microwave link may obtain the bandwidthinformation of the microwave link in the current modulation mode whenthe current modulation mode of the microwave link is lower than theoptimal modulation mode, and sends the bandwidth information to theendpoint of the service connection which passes through the microwavelink. Therefore, the endpoint of the service connection may adjust theservice policy according to the bandwidth information, so that abandwidth of the microwave link can meet a service requirement, andservice congestion can be avoided.

The following describes a network node provided in an embodiment of thepresent invention. FIG. 5 illustrates a structure of a network nodeaccording to a first embodiment. The network node includes: a detectingunit 501, configured to detect a current modulation mode of a microwavelink; an obtaining unit 502, configured to obtain bandwidth informationof the microwave link in the current modulation mode that is detected bythe detecting unit sol; and a sending unit 503, configured to send thebandwidth information obtained by the obtaining unit 502 to an endpointof a service connection through the service connection which passesthrough the microwave link, so that the endpoint of the serviceconnection adjusts a service policy according to the bandwidthinformation.

It can be known from the preceding that, in this embodiment, the networknode may obtain the bandwidth information of the microwave link in thecurrent modulation mode, and sends the bandwidth information to theendpoint of the service connection which passes through the microwavelink. Therefore, the endpoint of the service connection may adjust theservice policy according to the bandwidth information, so that abandwidth of the microwave link can meet a service requirement, andservice congestion can be avoided.

FIG. 6 illustrates a structure of a network node according to a secondembodiment. The network node includes: a detecting unit 601, configuredto detect a current modulation mode of a microwave link; a judging unit602, configured to judge whether the current modulation mode that isdetected by the detecting unit 601 is lower than an optimal modulationmode; an obtaining unit 603, configured to, when the judging unit 602judges that the current modulation mode that is detected by thedetecting unit is lower than the optimal modulation mode, obtainbandwidth information of the microwave link in the current modulationmode that is detected by the detecting unit; and a sending unit 604,configured to send the bandwidth information obtained by the obtainingunit 603 to an endpoint of a service connection through the serviceconnection which passes through the microwave link, so that the endpointof the service connection adjusts a service policy according to thebandwidth information.

In an embodiment of the present invention, when the judging unit 602judges that the current modulation mode is the optimal modulation mode,the sending unit 604 stops sending the bandwidth information to theendpoint of the service connection which passes through the microwavelink, so that the endpoint of the service connection uses a normalservice policy to perform service processing.

It can be known from the preceding that, in this embodiment, the networknode may obtain the bandwidth information of the microwave link in thecurrent modulation mode when the current modulation mode of themicrowave link is lower than the optimal modulation mode, and sends thebandwidth information to the endpoint of the service connection whichpasses through the microwave link. Therefore, the endpoint of theservice connection may adjust the service policy according to thebandwidth information, so that a bandwidth of the microwave link canmeet a service requirement, and service congestion can be avoided.

FIG. 7 illustrates a structure of a network node according to a thirdembodiment. The network node may include: a receiving unit 701configured to receive bandwidth information of a microwave link in acurrent modulation mode, where the bandwidth information is sent by anetwork node that is attached by the microwave link, and a determiningunit 702 configured to, according to a preset corresponding relationshipbetween bandwidth information and a service policy, determine a servicepolicy corresponding to the bandwidth information that is received bythe receiving unit 701.

In an embodiment of the present invention, the determining unit 702 isfurther configured to determine the service policy as a normal servicepolicy when the receiving unit 701 does not receive the bandwidthinformation in preset time.

A processing unit 703 is configured to perform service processingaccording to the service policy that is determined by the determiningunit 702.

It can be known from the preceding that, in this embodiment, the networknode may receive the bandwidth information of the microwave link in thecurrent modulation mode, where the bandwidth information is sent by thenetwork node that is attached by the microwave link, and the servicepolicy is adjusted according to the bandwidth information, so that abandwidth of the microwave link can meet a service requirement, andservice congestion can be avoided.

An embodiment of the present invention further provides a communicationsystem. The communication system includes a network node provided in anembodiment of the present invention.

An information exchange between each module in the preceding apparatusand system and an implementation process in the apparatus and system arebased on the same conception with the method embodiment of the presentinvention, and therefore, the specific content may be made reference tothe description of the method embodiment of the present invention, whichis not further described here.

Persons of ordinary skill in the art may understand that all or part ofthe procedures of the method in the preceding embodiments may beimplemented by a program instructing relevant hardware including aprocessor. The program may be stored in a computer readable storagemedium. When the program runs, the procedures of the method in thepreceding embodiments. The storage medium may be a magnetic disk, aread-only memory (ROM), or a random access memory (RAM).

The bandwidth information notification method, the network node, and thecommunication system that are provided in the embodiments of the presentinvention are described in detail in the preceding. The description ofthe preceding embodiments is only used for helping to understand themethod and idea of the present invention; meanwhile, those skilled inthe art may make variations to the specific implementation and theapplication scope according to the idea of the present invention. Inconclusion, the content of this specification shall not be construed asa limitation to the present invention.

What is claimed is:
 1. A method, comprising: obtaining, by a networknode, bandwidth information of a microwave link; and sending, by thenetwork node, a plurality of operation, administration and maintenance(OAM) messages carrying the bandwidth information to an endpoint;wherein when a bandwidth of the microwave link has changed, a first oneor more OAM messages of the plurality of OAM messages are sent morequickly than at least one of the rest of the plurality of OAM messages.2. The method according to claim 1, wherein obtaining the bandwidthinformation of the microwave link comprises: detecting, by the networknode, a modulation mode of the microwave link; and obtaining, by thenetwork node, bandwidth information of the microwave link under themodulation mode.
 3. The method according to claim 1, wherein sending, bythe network node, the plurality of OAM messages carrying the bandwidthinformation to an endpoint comprises: sending, by the network node, theplurality of OAM messages carrying the bandwidth information to theendpoint when a bandwidth of the microwave link is not a full bandwidth.4. The method according to claim 3, further comprising: stoppingsending, by the network node, OAM messages for bandwidth notification tothe endpoint when the bandwidth of the microwave link is the fullbandwidth.
 5. A method, comprising: receiving, by an endpoint, aplurality of operation, administration and maintenance (OAM) messagescarrying bandwidth information of a microwave link; and adjusting, bythe endpoint, a service policy according to the bandwidth information.6. The method according to claim 5, wherein when a bandwidth of themicrowave link has changed, a first one or more OAM messages of theplurality of OAM messages are received more quickly than at least one ofthe rest of the plurality of OAM messages.
 7. A network node,comprising: a processor, configured to obtain bandwidth information of amicrowave link; and a transmitter, configured to send a plurality ofoperation, administration and maintenance (OAM) messages carrying thebandwidth information to an endpoint; wherein when a bandwidth of themicrowave link has changed, a first one or more OAM messages of theplurality of OAM messages are sent more quickly than at least one of therest of the plurality of OAM messages.
 8. The network node according toclaim 7, wherein the processor is configured to: detect a modulationmode of the microwave link; and obtain a bandwidth information of themicrowave link under the modulation mode.
 9. The network node accordingto claim 7, wherein the transmitter is configured to: send the pluralityof OAM messages carrying the bandwidth information to the endpoint whena bandwidth of the microwave link is not a full bandwidth.
 10. Thenetwork node according to claim 9, wherein the transmitter is furtherconfigured to: stop sending OAM messages for bandwidth notification tothe endpoint when the bandwidth of the microwave link is the fullbandwidth.
 11. An endpoint, comprising: a receiver, configured toreceive a plurality of operation, administration and maintenance (OAM)messages carrying bandwidth information of a microwave link; and aprocessor, configured to adjust a service policy according to thebandwidth information.
 12. The endpoint according to claim 11, whereinwhen a bandwidth of the microwave link has changed, a first one or moreOAM messages of the plurality of OAM messages are received more quicklythan at least one of the rest of the plurality of OAM messages.